1. Field of the Invention
The present invention relates to a color printer and more particularly, to a color printer for driving a ribbon according to the count of an optical encoding disk so as to economize the length of the ribbon.
2. Description of the Prior Art
Please refer to FIG. 1, FIG. 1 is a perspective view of a ribbon apparatus of a conventional color printer 10. As shown in FIG. 1, the ribbon apparatus of the color printer 10 includes a ribbon 12, two light sources 14, 16, and two sensors 18, 20. The ribbon 12 includes a plurality of sequentially arranged dye regions 22. Each dye region 22 includes four dye areas 24, 26, 28, 30 for placing yellow dye, magenta dye, cyan dye, and overcoating dye. An opaque dividing section 32 is located between an overcoating dye area 30 and a yellow dye area 24. An opaque dividing section 34 and a transparent dividing section 36 are installed between the yellow dye area 24 and a magenta dye area 26. An opaque dividing section 34 and a transparent dividing section 36 are installed between the magenta dye area 26 and a cyan dye area 28. An opaque dividing section 34 and a transparent dividing section 36 are installed between the cyan dye area 28 and the overcoating dye area 30.
The light sources 14, 16 are located on one side of the ribbon 12 for producing light beams 38, 40 of two predetermined colors. The sensors 18, 20, corresponding to the light sources 14, 16, are located on the opposite side of the ribbon 12. The sensors 18, 20 are used to detect light beams 38, 40 penetrating through the ribbon 12 and produce corresponding signals to determine the position of the ribbon 12. The detection of an opaque dividing section 32 signals the beginning position of a new dye region 22 of the ribbon 12, and also corresponds to the beginning position of a yellow dye area 24. The detection of an opaque dividing section 34 and a transparent dividing section 36 by the sensors 18, 20 corresponds to the beginning position of the magenta dye area 26, cyan dye area 28, or overcoating dye area 30. The reservation of opaque dividing sections 34 and transparent dividing sections 36 for detection of the position of the ribbon 12 is a disadvantage of the prior art color printer 10 because it decreases the effective utilization of the ribbon 12, resulting in higher production costs of the ribbon 12.